It is difficult to sync with stat updaters, stats are (should be)
monotonic so users can calculate differences from a reference.

Signed-off-by: Michal Koutný <mkoutny@suse.com>
---
 block/blk-cgroup.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 9ed93d91d754a..b77219dd8b061 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -659,6 +659,7 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
 	struct blkcg_gq *blkg;
 	int i;
 
+	pr_warn_once("blkio.%s is deprecated\n", cftype->name);
 	mutex_lock(&blkcg_pol_mutex);
 	spin_lock_irq(&blkcg->lock);
 
-- 
2.48.1